CCS811 - Gas Sensor#

Driver for the Cambridge CMOS Sensors CCS811 gas and indoor air quality sensor.

CCS811 usage example code#

Basic example for initializing measuring equivalent Co2 and TVOC level.

#include "sl_i2cspm_instances.h"
#include "sl_ccs811.h"

int main( void )
{

  ...

  // Initialize sensor and set measure mode
  sl_ccs811_init(sl_i2cspm_sensor_gas);
  sl_ccs811_set_measure_mode(sl_i2cspm_sensor_gas, CCS811_MEASURE_MODE_DRIVE_MODE_1SEC);

  uint16_t eco2;
  uint16_t tvoc;

  while (true) {

    if ( sl_ccs811_is_data_available(sl_i2cspm_sensor_gas) ) {
      sl_ccs811_get_measurement(sl_i2cspm_sensor_gas, &eco2, &tvoc);
    }

    ...

  }

}

Modules#

CCS881 - Gas Sensor Details

Functions#

sl_status_t

sl_ccs811_init(sl_i2cspm_t *i2cspm)

Initialize the chip.

sl_status_t

sl_ccs811_deinit(sl_i2cspm_t *i2cspm)

De-initialize the chip.

sl_status_t

sl_ccs811_get_hardware_id(sl_i2cspm_t *i2cspm, uint8_t *hwID)

Reads Hardware ID from the CCS811 sensor.

sl_status_t

sl_ccs811_set_measure_mode(sl_i2cspm_t *i2cspm, uint8_t measMode)

Set the measurement mode of the CCS811 sensor.

sl_status_t

sl_ccs811_update_firmware(sl_i2cspm_t *i2cspm, const uint8_t *firmware, uint32_t length)

Perform a firmware update of the CCS811 sensor.

sl_status_t

sl_ccs811_read_firmware_version(sl_i2cspm_t *i2cspm, uint16_t *fw_version)

Read out current firmware of the CCS811 sensor.

sl_status_t

sl_ccs811_get_status(sl_i2cspm_t *i2cspm, uint8_t *status)

Read the status of the CCS811 sensor.

sl_status_t

sl_ccs811_read_mailbox(sl_i2cspm_t *i2cspm, uint8_t id, uint8_t length, uint8_t *data)

Read data from a specific Mailbox address.

sl_status_t

sl_ccs811_start_application(sl_i2cspm_t *i2cspm)

Switch the CCS811 chip from boot to application mode.

sl_status_t

sl_ccs811_software_reset(sl_i2cspm_t *i2cspm)

Perform software reset on the CCS811.

bool

sl_ccs811_is_data_available(sl_i2cspm_t *i2cspm)

Check whether new measurement data is available.

sl_status_t

sl_ccs811_get_measurement(sl_i2cspm_t *i2cspm, uint16_t *eco2, uint16_t *tvoc)

Read measurement data (eCO2 and TVOC) from the CCS811 sensor.

sl_status_t

sl_ccs811_get_raw_data(sl_i2cspm_t *i2cspm, uint16_t *current, uint16_t *rawData)

Get the latest readings from the sense resistor of the CCS811 sensor.

sl_status_t

sl_ccs811_set_env_data(sl_i2cspm_t *i2cspm, int32_t tempData, uint32_t rhData)

Write temperature and humidity values to the environmental data regs.

Function Documentation#

sl_ccs811_init#

sl_status_t sl_ccs811_init (sl_i2cspm_t * i2cspm)

Initialize the chip.

Parameters

[in]

i2cspm

The I2CSPM instance to use.

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_INITIALIZATION: Initialization was unsuccessful

Definition at line 137 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_deinit#

sl_status_t sl_ccs811_deinit (sl_i2cspm_t * i2cspm)

De-initialize the chip.

Parameters

[in]

i2cspm

The I2CSPM instance to use.

Returns

Return values

SL_STATUS_OK: Success

Definition at line 149 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_get_hardware_id#

sl_status_t sl_ccs811_get_hardware_id (sl_i2cspm_t * i2cspm, uint8_t * hwID)

Reads Hardware ID from the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[out]	hwID	The Hardware ID of the chip (should be 0x81)

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 165 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_set_measure_mode#

sl_status_t sl_ccs811_set_measure_mode (sl_i2cspm_t * i2cspm, uint8_t measMode)

Set the measurement mode of the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[in]	measMode	The desired measurement mode

This function must be called before reading measurements from the sensor.

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 184 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_update_firmware#

sl_status_t sl_ccs811_update_firmware (sl_i2cspm_t * i2cspm, const uint8_t * firmware, uint32_t length)

Perform a firmware update of the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[in]	firmware	A buffer containing the contents of the firmware update
[in]	length	The length of the firmware update array

This function overwrites the existing firmware, irrespective of the version number.

Returns

Return values

SL_STATUS_OK: Firmware upgrade successful
SL_STATUS_FAIL: Firmware upgrade failed

Definition at line 207 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_read_firmware_version#

sl_status_t sl_ccs811_read_firmware_version (sl_i2cspm_t * i2cspm, uint16_t * fw_version)

Read out current firmware of the CCS811 sensor.

Parameters

[in]	i2cspm	The i2cspm instance to use
[out]	fw_version	The current application firmware. The top 4 bits contain the major firmware version, the next 4 bits contain the minor and the last 8 bits contain the patch version.

Definition at line 223 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_get_status#

sl_status_t sl_ccs811_get_status (sl_i2cspm_t * i2cspm, uint8_t * status)

Read the status of the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[out]	status	The content of the CCS811 Status Register

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 239 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_read_mailbox#

sl_status_t sl_ccs811_read_mailbox (sl_i2cspm_t * i2cspm, uint8_t id, uint8_t length, uint8_t * data)

Read data from a specific Mailbox address.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[in]	id	The address of the Mailbox register
[in]	length	The number of bytes to read
[out]	data	The data read from the sensor

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 261 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_start_application#

sl_status_t sl_ccs811_start_application (sl_i2cspm_t * i2cspm)

Switch the CCS811 chip from boot to application mode.

Parameters

[in]

i2cspm

The I2CSPM instance to use

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission failure
SL_STATUS_NOT_AVAILABLE: Application firmware is not present in the CCS811 device
SL_STATUS_INVALID_STATE: Chip firmware did not switch to application mode

Definition at line 276 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_software_reset#

sl_status_t sl_ccs811_software_reset (sl_i2cspm_t * i2cspm)

Perform software reset on the CCS811.

Parameters

[in]

i2cspm

The I2CSPM instance to use

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 289 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_is_data_available#

bool sl_ccs811_is_data_available (sl_i2cspm_t * i2cspm)

Check whether new measurement data is available.

Parameters

[in]

i2cspm

The I2CSPM instance to use

Returns

True if new data available, otherwise false

Definition at line 301 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_get_measurement#

sl_status_t sl_ccs811_get_measurement (sl_i2cspm_t * i2cspm, uint16_t * eco2, uint16_t * tvoc)

Read measurement data (eCO2 and TVOC) from the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use
[out]	eco2	The equivalent CO2 level (in ppm) read from the sensor
[out]	tvoc	The TVOC level (in ppb) read from the sensor

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 320 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_get_raw_data#

sl_status_t sl_ccs811_get_raw_data (sl_i2cspm_t * i2cspm, uint16_t * current, uint16_t * rawData)

Get the latest readings from the sense resistor of the CCS811 sensor.

Parameters

[in]	i2cspm	The I2CSPM instance to use
[out]	current	The value of current through the sensor
[out]	rawData	The raw ADC reading of the voltage across the sensor with the selected current

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 340 of file hardware/driver/ccs811/inc/sl_ccs811.h

sl_ccs811_set_env_data#

sl_status_t sl_ccs811_set_env_data (sl_i2cspm_t * i2cspm, int32_t tempData, uint32_t rhData)

Write temperature and humidity values to the environmental data regs.

Parameters

[in]	i2cspm	The I2CSPM instance to use.
[in]	tempData	The environmental temperature in milliCelsius
[in]	rhData	The relative humidity in millipercent

Returns

Return values

SL_STATUS_OK: Success
SL_STATUS_TRANSMIT: I2C transmission error

Definition at line 359 of file hardware/driver/ccs811/inc/sl_ccs811.h